240v/50a Welder Problem.

markknx

markknx

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I recently bought a Eastwood Mig 250 welding Machine specs are 240v @ 47.3 A input. it is an inverter machine. The problem is it seems to be welding way to hot. Now here is where it gets odd I took it back to Eastwood's show room and it welded fine in their shop. I checked the voltage at my outlet it was 245. the outlet is 35' from the breaker box, it is wired with 8 awg. wire. From the outlet to the machine there is a 15' extension cord made from 4/8 insulated cord. The cord on the welder is 8 awg. Anyone got any idea why this would be happening? By the way I am in the USA so all is 60Hz.

This issue was raised in a topic about the welder but I thought it may be a better question here.

Thanks up front for any help.
Mark
 
What was the voltage at their shop? You could just keep turning the heat down till it does what you want.
 
Is the problem the heat is too high or that the wire feed is slowing down?

You shouldn't be having a problem with the wire feed but I did have that problem with a much older and cheaper mig welder. Drawing current dropped the voltage to the motor and the wire feed speed slowed down. I changed the motor power supply to a PWM supply running on a regulated voltage and solved the problem. My Miller Cricket MIG welder also uses a simple rheostat controlled wire feed motor but I have not had problems with that welder. It just depends on the design specs, I guess. I am not intimately familiar with inverter welder technology but if it is similar to other inverter power supplies, it is probably capable of correcting for input voltage variations. If so, a drop in line voltage would cause an increase in line current which would drop the line voltage even more which could adversely affect the feed motor.

Since the welder runs OK at the showroom, you may have a problem with supply voltage. You would need to check the voltage while welding. Have an assistant make that measurement. 8AWG wire should be sufficient but it is possible that there is a poor connection somewhere which is dropping the voltage under load.
 
i'm questioning also the voltage at the shop where you bought the welder at,
was the supply taken from single phase power (240VAC) or were 2 legs stripped off a transformed 3 phase circuit @ 208VAC to get the single phase ?
 
David VanNorman said:
What was the voltage at their shop? You could just keep turning the heat down till it does what you want.
Click to expand...
David, Yes I have been playing with that but I am concerned about a bad power "burn out".

RJ, the wire speed seems to be feeding good. Not like it is spitting or burning back. I can hear and feel the weld is way hot. Also I can dial the machine in to weld pretty darn good, just not any were near what the chart is calling for. Say I set the machine for 1/8 I can weld on 3/8 or 1/2 and it runs good. Trust me when I say if I was sure I'm not hurting the machine I would be glad with the extra heat.

I did do a inspection of the wire circuit, I found one leg at the breaker that had a turn I Could get out of the clamp screw (didn't fix it though.)

Ulma Dr., yes that entered my mind. The store Manager is looking into that. any Idea what size wire is required for a 208 50 amp circuit? Reason I ask is thinking back it seem like his outlet had 3/4 thin wall conduit. I think 8AWG would be mighty tight I that.

You know guys it just occurred to me I could try the machine on 120v and see how it runs (it is dual voltage) I can use a different circuit and the use the two outlet I have pulled off of the 220 circuit to see if it welds hot there. May be able to rule some things out.

Also waiting on Eastwood's tech Dept. to call me back with what a normal amp draw should be. I could then clamp an amp meter on and see if it is close.

Thanks for all the input guys,
Mark
 
for a short run i'd heavily consider using #6 wire for single phase duty for 50 amp service
 
I used #6 power cable for mine, too. This is probably not it... but here are a couple of other ideas: are you running DCEP or DCEN polarity? What gas are you running? Did you use their gas at the showroom, or did you bring your own bottle? Pure Argon, 75/25 mix, and C02 all have very different welding characteristics. Just curious because you wouldn't think one gauge power supply cable would make that big of a difference unless you're running at full 250A output.

GG
 
GG, I am using nr211 flux core wire DCEN. No gas. Yes I would not think the wire gage would make that big of a difference. And if it did I would think it would make it run colder, but I am not an electrician.
 
That sounds correct. I've never used flux core wire before, but I know it requires the opposite polarity as conventional MIG welding, which is DCEP. Is it possible for you to get a line voltage reading at the power cord of the welder while welding at pull power? Low line voltage would reduce welding output power and increase heat build-up inside the machine. Usually the new inverter welders are built with quite a bit of tolerance for low voltage since that is the single most common problem in a home/hobby shop. Weld.com even did side by side tests on inverter duty cycles to try to make them go into shut down mode, and it was nearly impossible to do on 240v machines.

Just grasping at straws here... But are you sure the power plug is wired correctly? Your machine will most likely run on 120v, but not perform well. Having tried it at the store and it working fine probably eliminated that possibility.

Very strange.

Sent using Tapatalk from someplace deep inside the garage
 
Could not find an issue with my power, and Eastwood says they are running 220, so the machine went back. Not knocking the machine, it just didn't work for me. Lincoln power mig 210 mp on it's way. This will help let me know if there is an issue with my electric or just an issue with the Eastwood machines inverter.

Mark
 
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